.circle {
  $circleCount: 12;
  $animationDuration: 1.2s;

  position: relative;
  margin: auto;

  .child {
    width: 100%;
    height: 100%;
    position: absolute;
    left: 0;
    top: 0;

    div {
      content: '';
      display: block;
      margin: 0 auto;
      width: 15%;
      height: 15%;
      line-height: 0;
      overflow: hidden;
      border-radius: 100%;
      animation: sk-circleBounceDelay $animationDuration infinite ease-in-out both;
    }
  }

  @for $i from 2 through $circleCount {
    .circle#{$i} {
      transform: rotate(360deg / $circleCount * ($i - 1));
      div {
        animation-delay: - $animationDuration + $animationDuration / $circleCount * ($i - 1);
      }
    }
  }
}

@keyframes sk-circleBounceDelay {
  0%, 80%, 100% { transform: scale(0) }
  40% { transform: scale(1.0) }
}
